By-elections - votes scheduled between regular elections - are taken by the media as the mid-term popularity indicators, which often ignores the local decisions behind a vote and the smaller turnouts that often take place.

But by any measure this was an unsual result. Labour's share of the vote was down 20% on its 2010 figure, while the Conservatives dropped by almost 23% and the Liberal Democrats lost their deposit after netting 4.59% of the votes – down 7% on the 2010 general election result.

Galloway's result represented the first byelection win by an independent since 1973 and the first time an opposition party has lost one of its seats since the Romsey byelection in 2000.

This graphic, by Craig Bloodworth at The Information Lab shows how each party has won or lost since 1979.

Galloway's 36.6% swing from Labout puts his win as one of the biggest in recent history, only behind Liberal Simon Hughes' victory with a 44% swing in Bermondsey in 1983.

That kind of swing is unusual, as you can see from this chart.

45 seats have changed hands in by-elections since 1979, in a quarter of the 165 by-elections which took place. The Liberals and latterly Lib Dems have been the big gainers, as the traditional recipients of the protest vote - at least before 2010: 20 seats gained and none lost.

The full data is below - care of a combination of British Political Facts, Butler & Butler (yes, it's an actual book), Guardian archives and Wikipedia. What can you do with it?